diff --git a/gns3server/compute/qemu/__init__.py b/gns3server/compute/qemu/__init__.py
index 663ee37f..bca490cc 100644
--- a/gns3server/compute/qemu/__init__.py
+++ b/gns3server/compute/qemu/__init__.py
@@ -48,6 +48,7 @@ class Qemu(BaseManager):
 
         super().__init__()
         self._guest_cid_lock = asyncio.Lock()
+        self.config_disk = "config.img"
         self._init_config_disk()
 
     async def create_node(self, *args, **kwargs):
@@ -353,12 +354,10 @@ class Qemu(BaseManager):
         Initialize the default config disk
         """
 
-        self.config_disk = "config.img"
         try:
             self.get_abs_image_path(self.config_disk)
-        except (NodeError, ImageMissingError) as e:
-            config_disk_zip = get_resource("compute/qemu/resources/{}.zip"
-                                           .format(self.config_disk))
+        except (NodeError, ImageMissingError):
+            config_disk_zip = get_resource("compute/qemu/resources/{}.zip".format(self.config_disk))
             if config_disk_zip and os.path.exists(config_disk_zip):
                 directory = self.get_images_directory()
                 try:
@@ -366,5 +365,4 @@ class Qemu(BaseManager):
                 except OSError as e:
                     log.warning("Config disk creation: {}".format(e))
             else:
-                log.warning("Config disk: image '{}' missing"
-                            .format(self.config_disk))
+                log.warning("Config disk: image '{}' missing".format(self.config_disk))
diff --git a/gns3server/compute/qemu/qemu_vm.py b/gns3server/compute/qemu/qemu_vm.py
index 63a99c72..a89076cb 100644
--- a/gns3server/compute/qemu/qemu_vm.py
+++ b/gns3server/compute/qemu/qemu_vm.py
@@ -131,17 +131,17 @@ class QemuVM(BaseNode):
         # config disk
         self.config_disk_name = self.manager.config_disk
         self.config_disk_image = ""
-        if not shutil.which("mcopy"):
-            log.warning("Config disk: 'mtools' are not installed.")
-            self.config_disk_name = ""
-        else:
-            try:
-                self.config_disk_image = self.manager.get_abs_image_path(
-                    self.config_disk_name)
-            except (NodeError, ImageMissingError) as e:
-                log.warning("Config disk: image '{}' missing"
-                            .format(self.config_disk_name))
+        if self.config_disk_name:
+            if not shutil.which("mcopy"):
+                log.warning("Config disk: 'mtools' are not installed.")
                 self.config_disk_name = ""
+            else:
+                try:
+                    self.config_disk_image = self.manager.get_abs_image_path(self.config_disk_name)
+                except (NodeError, ImageMissingError) as e:
+                    log.warning("Config disk: image '{}' missing"
+                                .format(self.config_disk_name))
+                    self.config_disk_name = ""
 
         log.info('QEMU VM "{name}" [{id}] has been created'.format(name=self._name, id=self._id))
 
diff --git a/tests/compute/qemu/test_qemu_vm.py b/tests/compute/qemu/test_qemu_vm.py
index 7df7df61..6b69ab75 100644
--- a/tests/compute/qemu/test_qemu_vm.py
+++ b/tests/compute/qemu/test_qemu_vm.py
@@ -337,6 +337,7 @@ def test_set_qemu_path_kvm_binary(vm, fake_qemu_binary):
 
 async def test_set_platform(compute_project, manager):
 
+    manager.config_disk = None  # avoids conflict with config.img support
     with patch("shutil.which", return_value="/bin/qemu-system-x86_64") as which_mock:
         with patch("gns3server.compute.qemu.QemuVM._check_qemu_path"):
             vm = QemuVM("test", "00010203-0405-0607-0809-0a0b0c0d0e0f", compute_project, manager, platform="x86_64")
diff --git a/tests/compute/test_manager.py b/tests/compute/test_manager.py
index bceb9e20..e257e763 100644
--- a/tests/compute/test_manager.py
+++ b/tests/compute/test_manager.py
@@ -18,7 +18,7 @@
 import uuid
 import os
 import pytest
-from unittest.mock import patch
+from unittest.mock import patch, MagicMock
 from tests.utils import asyncio_patch
 
 from gns3server.compute.vpcs import VPCS
@@ -41,6 +41,7 @@ async def vpcs(loop, port_manager):
 async def qemu(loop, port_manager):
 
     Qemu._instance = None
+    Qemu._init_config_disk = MagicMock()  # do not create the config.img image
     qemu = Qemu.instance()
     qemu.port_manager = port_manager
     return qemu